Brassinosteroids(BRs)are essential phytohormones that broadly regulate plant growth,development,and adaptation to biotic and abiotic stresses.In Arabidopsis,apoplastic BR molecules are perceived by a plasma membrane-l...Brassinosteroids(BRs)are essential phytohormones that broadly regulate plant growth,development,and adaptation to biotic and abiotic stresses.In Arabidopsis,apoplastic BR molecules are perceived by a plasma membrane-localized receptor complex comprising the ligand-binding receptor BRI1 and the co-receptor BAK1.While negative regulators of the BR receptor complex,such as BKI1,BIR3,and PUB12/13,have been well characterized,how BRI1 and BAK1 are positively modulated in the BR pathway remains largely unknown.In this study,a genetic screen involving overexpression of RLP genes in the bak1-3 bkk1-1 double mutant reveals that enhanced RLP51 expression partially suppresses the BR-deficient phenotypes of bak1-3 bkk1-1.RLP51 overexpression also partially rescues the weak bri1 mutant allele,bri1-301.Although the rlp51 single mutant exhibits wild-type-like phenotypes,it enhances BR-defective phenotypes in bri1-301 and bak1 serk1 mutants.RLP51 is next found to interact with both BRI1 and BAK1 without affecting BRI1–BAK1 interaction.Critically,co-expression of RLP51 with BRI1 or BAK1 significantly increases BRI1 and BAK1 protein abundances.RLP51 appears to promote protein synthesis rather than stabilize BRI1 and BAK1 proteins.Thus,our study identifies RLP51 as a positive regulator of BR signaling that enhances the protein levels of BRI1 and BAK1.展开更多
Synergistic removal of aniline by carbon nanotubes and the enzymes of Delftia sp. XYJ6, a newly isolated bacterial strain for biodegrading aniline, was investigated. It showed that biodegradation rate of aniline was i...Synergistic removal of aniline by carbon nanotubes and the enzymes of Delftia sp. XYJ6, a newly isolated bacterial strain for biodegrading aniline, was investigated. It showed that biodegradation rate of aniline was increased with the augment of protein concentration in cell-free extract of Delftia sp. XYJ6. The adsorption amount of aniline by multi-walled carbon nanotubes （MWCNTs） was slightly higher than that by single-walled carbon nanotubes （SWCNTs）, however the adsorption amount of protein of Delftia sp. XYJ6 by MWCNTs was lower than that by SWCNTs. Much more amount of aniline could be removed by CE of Delftia sp. XYJ6 in the presence of SWCNTs than MWCNTs, which indicated that an efficient reaction between aniline and enzymes of Delftia sp. XYJ6 on the surface of SWCNTs played a key role in the rapid enzymatic biodegradation of aniline. This study is not previously reported and may be useful in basic research and the removal of aniline from wastewater.展开更多
Nitrogen(N)is an essential macronutrient for plants and profoundly affects crop yields and qualities.Ammonium(NH4+)and nitrate(NO3-)are major inorganic N forms absorbed by plants from the surrounding environments.Intr...Nitrogen(N)is an essential macronutrient for plants and profoundly affects crop yields and qualities.Ammonium(NH4+)and nitrate(NO3-)are major inorganic N forms absorbed by plants from the surrounding environments.Intriguingly,NH4+is usually toxic to plants when it serves as the sole or dominant N source.It is thus important for plants to coordinate the utilization of NH4+and the alleviation of NH4+toxicity.To fully decipher the molecular mechanisms underlying how plants minimize NH4+toxicity may broadly benefit agricultural practice.In the current minireview,we attempt to discuss recent discoveries in the strategies for mitigating NH4+toxicity in plants,which may provide potential solutions for improving the nitrogen use efficiency(NUE)and stress adaptions in crops.展开更多
Ammonium(NH_(4)^(+))and nitrate(NO_(3)^(-))are major inorganic nitrogen(N)sources for plants.When serving as the sole or dominant N supply,NH_(4)^(+)often causes root inhibition and shoot chlorosis in plants,known as ...Ammonium(NH_(4)^(+))and nitrate(NO_(3)^(-))are major inorganic nitrogen(N)sources for plants.When serving as the sole or dominant N supply,NH_(4)^(+)often causes root inhibition and shoot chlorosis in plants,known as ammonium toxicity.NO_(3)^(-) usually causes no toxicity and can mitigate ammonium toxicity even at low concentrations,referred to as nitrate-dependent alleviation of ammonium toxicity.Our previous studies indicated a NO_(3)^(-) efflux channel SLAH3 is involved in this process.However,whether additional components contribute to NO_(3)^(-)-mediated NH_(4)^(+)detoxification is unknown.Previously,mutations in NO_(3)^(-) transporter NRT1.1 were shown to cause enhanced resistance to high concentrations of NH_(4)^(+).Whereas,in this study,we found when the high-NH_(4)^(+) medium was supplemented with low concentrations of NO_(3)^(-),nrt1.1 mutant plants showed hyper-sensitive phenotype instead.Furthermore,mutation in NRT1.1 caused enhanced medium acidification under high-NH_(4)^(+)/Iow-NO_(3)^(-) condition,suggesting NRT1.1 regulates ammonium toxicity by facilitating H+uptake.Moreover,NRT1.1 was shown to interact with SLAH3 to form a transporter-channel complex.Interestingly,SLAH3 appeared to affect NO_(3)^(-) influx while NRT1.1 influenced NO_(3)^(-) efflux,suggesting NRT1.1 and SLAH3 regulate each other at protein and/or gene expression levels.Our study thus revealed NRT1.1 and SLAH3 form a functional unit to regulate nitrate-dependent alleviation of ammonium toxicity through regulating NO_(3)^(-) transport and balancing rhizosphere acidification.展开更多
A promising bacterial strain for biodegradingmicrocystin-LR(MC-LR)as the sole carbon and nitrogensource was successfully isolated from Lake Dianchi,China.The strain was identified as Sphingopyxis sp.USTB-05,which was ...A promising bacterial strain for biodegradingmicrocystin-LR(MC-LR)as the sole carbon and nitrogensource was successfully isolated from Lake Dianchi,China.The strain was identified as Sphingopyxis sp.USTB-05,which was the first isolated MCs-biodegradingSphingopyxis sp.in China.The average biodegradationrate of MC-LR by Sphingopyxis sp.USTB-05 was 28.8mg·L^(-1)per day,which was apparently higher than those ofother bacteria reported so far.The optimal temperature andpH for both strain USTB-05 growth and MC-LRbiodegradation were 30℃and 7.0,respectively.Therelease of MC-LR from the cyanobacterial cells collectedfrom Lake Guishui and the biodegradation of MC-LR byboth strain and cell-free extract(CE)were investigated.The results indicated that MC-LR with the initialconcentration of 4.0 mg·L^(-1)in water was biodegraded bySphingopyxis sp.USTB-05 within 4 d,while MC-LR withthe initial concentration of 28.8 mg·L^(-1)could be completelyremoved in 3 h by CE of Sphingopyxis sp.USTB-05 containing 350 mg·L^(-1)protein.During enzymaticbiodegradation of MC-LR,two intermediate metabolitesand a dead-end product were observed on an HPLCchromatogram.Moreover,the similar scanning profiles ofMC-LR and its metabolic products indicate that the Addaside-chain of MC-LR was kept intact in all products.展开更多
基金supported by the National Natural Science Foundation of China(32370295 and 32170280 to K.H.)Foundation of Science and Technology of Gansu Province(22ZD6NA049)+3 种基金the Fundamental Research Funds for the Central Universities(lzujbky-2021-kb05 to Y.F.and lzujbky-2023-kb05 to P.L.)the Science and Technology Department of Gansu Province(24JRRA392 to K.H.and 23JRRA1132 to C.X.)China Postdoctoral Science Foundation(2024M751259 and GZB20240285 to B.L.)Science and Technology Program of Gansu Province(25JRRA718 to B.L.).
文摘Brassinosteroids(BRs)are essential phytohormones that broadly regulate plant growth,development,and adaptation to biotic and abiotic stresses.In Arabidopsis,apoplastic BR molecules are perceived by a plasma membrane-localized receptor complex comprising the ligand-binding receptor BRI1 and the co-receptor BAK1.While negative regulators of the BR receptor complex,such as BKI1,BIR3,and PUB12/13,have been well characterized,how BRI1 and BAK1 are positively modulated in the BR pathway remains largely unknown.In this study,a genetic screen involving overexpression of RLP genes in the bak1-3 bkk1-1 double mutant reveals that enhanced RLP51 expression partially suppresses the BR-deficient phenotypes of bak1-3 bkk1-1.RLP51 overexpression also partially rescues the weak bri1 mutant allele,bri1-301.Although the rlp51 single mutant exhibits wild-type-like phenotypes,it enhances BR-defective phenotypes in bri1-301 and bak1 serk1 mutants.RLP51 is next found to interact with both BRI1 and BAK1 without affecting BRI1–BAK1 interaction.Critically,co-expression of RLP51 with BRI1 or BAK1 significantly increases BRI1 and BAK1 protein abundances.RLP51 appears to promote protein synthesis rather than stabilize BRI1 and BAK1 proteins.Thus,our study identifies RLP51 as a positive regulator of BR signaling that enhances the protein levels of BRI1 and BAK1.
基金supported by the National Natural Science Foundation of China (No. 203777008)the State Key Joint Laboratory of Environment Simulation and Pollution Control (No. 09K08ESPCT)the Fundamental Research Funds for the Central Universities (FRF-AS-10-001B)
文摘Synergistic removal of aniline by carbon nanotubes and the enzymes of Delftia sp. XYJ6, a newly isolated bacterial strain for biodegrading aniline, was investigated. It showed that biodegradation rate of aniline was increased with the augment of protein concentration in cell-free extract of Delftia sp. XYJ6. The adsorption amount of aniline by multi-walled carbon nanotubes （MWCNTs） was slightly higher than that by single-walled carbon nanotubes （SWCNTs）, however the adsorption amount of protein of Delftia sp. XYJ6 by MWCNTs was lower than that by SWCNTs. Much more amount of aniline could be removed by CE of Delftia sp. XYJ6 in the presence of SWCNTs than MWCNTs, which indicated that an efficient reaction between aniline and enzymes of Delftia sp. XYJ6 on the surface of SWCNTs played a key role in the rapid enzymatic biodegradation of aniline. This study is not previously reported and may be useful in basic research and the removal of aniline from wastewater.
基金supported by the National Natural Science Foundation of China(32170280)the 111 Project(B16022)the Fundamental Research Funds for the Central Universities(Izujbky-2019-kb05,Izujbky-2021-kb05)。
文摘Nitrogen(N)is an essential macronutrient for plants and profoundly affects crop yields and qualities.Ammonium(NH4+)and nitrate(NO3-)are major inorganic N forms absorbed by plants from the surrounding environments.Intriguingly,NH4+is usually toxic to plants when it serves as the sole or dominant N source.It is thus important for plants to coordinate the utilization of NH4+and the alleviation of NH4+toxicity.To fully decipher the molecular mechanisms underlying how plants minimize NH4+toxicity may broadly benefit agricultural practice.In the current minireview,we attempt to discuss recent discoveries in the strategies for mitigating NH4+toxicity in plants,which may provide potential solutions for improving the nitrogen use efficiency(NUE)and stress adaptions in crops.
基金supported by the National Natural Science Foundation of China(31870235,32170280)the 111 Project(B16022)the Fundamental Research Funds for the Central Universities(lzujbky-2019-kb05,lzujbky-2020-kb05,lzujbky-2021-it22)。
文摘Ammonium(NH_(4)^(+))and nitrate(NO_(3)^(-))are major inorganic nitrogen(N)sources for plants.When serving as the sole or dominant N supply,NH_(4)^(+)often causes root inhibition and shoot chlorosis in plants,known as ammonium toxicity.NO_(3)^(-) usually causes no toxicity and can mitigate ammonium toxicity even at low concentrations,referred to as nitrate-dependent alleviation of ammonium toxicity.Our previous studies indicated a NO_(3)^(-) efflux channel SLAH3 is involved in this process.However,whether additional components contribute to NO_(3)^(-)-mediated NH_(4)^(+)detoxification is unknown.Previously,mutations in NO_(3)^(-) transporter NRT1.1 were shown to cause enhanced resistance to high concentrations of NH_(4)^(+).Whereas,in this study,we found when the high-NH_(4)^(+) medium was supplemented with low concentrations of NO_(3)^(-),nrt1.1 mutant plants showed hyper-sensitive phenotype instead.Furthermore,mutation in NRT1.1 caused enhanced medium acidification under high-NH_(4)^(+)/Iow-NO_(3)^(-) condition,suggesting NRT1.1 regulates ammonium toxicity by facilitating H+uptake.Moreover,NRT1.1 was shown to interact with SLAH3 to form a transporter-channel complex.Interestingly,SLAH3 appeared to affect NO_(3)^(-) influx while NRT1.1 influenced NO_(3)^(-) efflux,suggesting NRT1.1 and SLAH3 regulate each other at protein and/or gene expression levels.Our study thus revealed NRT1.1 and SLAH3 form a functional unit to regulate nitrate-dependent alleviation of ammonium toxicity through regulating NO_(3)^(-) transport and balancing rhizosphere acidification.
基金The first and second authors did same contribution to this paper.This work was supported by the National Natural Science Foundation of China(Grant No.203777008)State Key Joint Laboratory of Environment Simulation and Pollution Control(No.09K08ESPCT),and Educational Committee of Beijing.
文摘A promising bacterial strain for biodegradingmicrocystin-LR(MC-LR)as the sole carbon and nitrogensource was successfully isolated from Lake Dianchi,China.The strain was identified as Sphingopyxis sp.USTB-05,which was the first isolated MCs-biodegradingSphingopyxis sp.in China.The average biodegradationrate of MC-LR by Sphingopyxis sp.USTB-05 was 28.8mg·L^(-1)per day,which was apparently higher than those ofother bacteria reported so far.The optimal temperature andpH for both strain USTB-05 growth and MC-LRbiodegradation were 30℃and 7.0,respectively.Therelease of MC-LR from the cyanobacterial cells collectedfrom Lake Guishui and the biodegradation of MC-LR byboth strain and cell-free extract(CE)were investigated.The results indicated that MC-LR with the initialconcentration of 4.0 mg·L^(-1)in water was biodegraded bySphingopyxis sp.USTB-05 within 4 d,while MC-LR withthe initial concentration of 28.8 mg·L^(-1)could be completelyremoved in 3 h by CE of Sphingopyxis sp.USTB-05 containing 350 mg·L^(-1)protein.During enzymaticbiodegradation of MC-LR,two intermediate metabolitesand a dead-end product were observed on an HPLCchromatogram.Moreover,the similar scanning profiles ofMC-LR and its metabolic products indicate that the Addaside-chain of MC-LR was kept intact in all products.
